Optical resonator with localized ion-implanted voids

Abstract

A high Q whispering gallery mode resonator with ion-implanted voids is described. A resonator device includes a resonator disk formed of an electrooptic material. The resonator disk includes a top surface, a bottom surface substantially parallel to the top surface, and a side structure between the top surface and the bottom surface. The side structure includes an axial surface along a perimeter of the resonator disk, where a midplane passes through the axial surface dividing the axial surface into symmetrical halves. The whispering gallery mode resonator disk includes voids localized at a particular depth from the top surface. At least one of the voids localized at the particular depth from the top surface is located at an outer extremity towards the perimeter of the resonator disk. The resonator device can further include a first electrode on the top surface and a second electrode on the bottom surface.

What is claimed is: 
     
       1. A resonator device, comprising:
 a whispering gallery mode resonator formed of an electrooptic material, the whispering gallery mode resonator comprising:
 a top surface; 
 a bottom surface substantially parallel to the top surface; 
 a side structure between the top surface and the bottom surface, the side structure comprises an axial surface along a perimeter of the whispering gallery mode resonator, wherein a midplane passes through the axial surface dividing the axial surface into symmetrical halves; and 
 voids localized within a particular depth range from the top surface, the particular depth range from the top surface being between the top surface and the midplane, the voids being bubbles formed within the electrooptic material, wherein at least one of the voids localized within the particular depth range from the top surface is located at an outer extremity towards the perimeter of the whispering gallery mode resonator; 
 
 a first electrode on the top surface of the whispering gallery mode resonator; and 
 a second electrode on the bottom surface of the whispering gallery mode resonator. 
 
     
     
       2. The resonator device of  claim 1 , wherein the whispering gallery mode resonator is disk shaped. 
     
     
       3. The resonator device of  claim 1 , wherein the whispering gallery mode resonator is ring shaped. 
     
     
       4. The resonator device of  claim 1 , wherein the whispering gallery mode resonator lacks voids between the bottom surface and the midplane. 
     
     
       5. The resonator device of  claim 1 , wherein the side structure is a convex side structure. 
     
     
       6. The resonator device of  claim 1 , the whispering gallery mode resonator further comprises:
 voids localized within a particular depth range from the bottom surface, the particular depth range from the bottom surface being between the bottom surface and the midplane, the voids being bubbles formed within the electrooptic material, wherein at least one of the voids localized within the particular depth range from the bottom surface is located at an outer extremity towards the perimeter of the whispering gallery mode resonator. 
 
     
     
       7. The resonator device of  claim 1 , the whispering gallery mode resonator further comprises:
 voids localized within a differing particular depth range from the top surface, the differing particular depth range from the top surface being between the top surface and the midplane, the voids being bubbles formed within the electrooptic material, wherein at least one of the voids localized within the differing particular depth range from the top surface is located at an outer extremity towards the perimeter of the whispering gallery mode resonator. 
 
     
     
       8. The resonator device of  claim 1 , the side structure of the whispering gallery mode resonator disk further comprises:
 a first chamfered edge between the top surface and the axial surface; and 
 a second chamfered edge between the bottom surface and the axial surface. 
 
     
     
       9. The resonator device of  claim 1 , wherein the resonator device supports a fundamental mode located in the midplane. 
     
     
       10. The resonator device of  claim 1 , wherein the particular depth range from the top surface is a range between 10 micrometers and 20 micrometers from the top surface. 
     
     
       11. The resonator device of  claim 1 , wherein the voids localized within the particular depth range from the top surface are ion-implanted voids located within the electrooptic material within the particular depth range from the top surface. 
     
     
       12. The resonator device of  claim 1 , wherein the voids are distributed across the whispering gallery mode resonator within the particular depth range from the top surface. 
     
     
       13. A lidar sensor system, comprising:
 a laser; 
 an optical coupler that is coupled to the laser; and 
 a whispering gallery mode resonator that is coupled to the optical coupler, the whispering gallery mode resonator formed of an electrooptic material, the whispering gallery mode resonator comprising:
 a top surface; 
 a bottom surface; 
 a side structure between the top surface and the bottom surface, the side structure comprises an axial surface along a perimeter of the whispering gallery mode resonator, wherein a midplane passes through the axial surface dividing the axial surface into symmetrical halves; and 
 voids localized within a particular depth range from the top surface, the particular depth range from the top surface being between the top surface and the midplane, the voids being bubbles formed within the electrooptic material, wherein at least one of the voids localized within the particular depth range from the top surface is located at an outer extremity towards the perimeter of the whispering gallery mode resonator. 
 
 
     
     
       14. The lidar sensor system of  claim 13 , wherein the bottom surface of the whispering gallery mode resonator is substantially parallel to the top surface of the whispering gallery mode resonator. 
     
     
       15. The lidar sensor system of  claim 13 , further comprising:
 a first electrode on the top surface of the whispering gallery mode resonator; and 
 a second electrode on the bottom surface of the whispering gallery mode resonator. 
 
     
     
       16. The lidar sensor system of  claim 13 , wherein the whispering gallery mode resonator is ring shaped. 
     
     
       17. The lidar sensor system of  claim 13 , wherein the whispering gallery mode resonator is disk shaped. 
     
     
       18. The lidar sensor system of  claim 13 , wherein the whispering gallery mode resonator lacks voids between the bottom surface and the midplane. 
     
     
       19. A method of manufacturing a whispering gallery mode resonator, comprising:
 directing an ion beam at a top surface of a wafer formed of an electrooptic material such that ions in the ion beam are implanted in the wafer and form voids distributed across the wafer within a particular depth range from the top surface of the wafer, the voids being bubbles formed within the electrooptic material; and 
 cutting the wafer with the voids distributed across the wafer within the particular depth range from the top surface to produce at least the whispering gallery mode resonator. 
 
     
     
       20. The method of  claim 19 , further comprising:
 directing the ion beam at a bottom surface of the wafer such that ions in the ion beam are implanted in the wafer and form voids distributed across the wafer within a particular depth range from the bottom surface of the wafer, wherein the wafer with the voids distributed within the particular depth range from the top surface and the voids distributed within the particular depth range from the bottom surface is cut to produce at least the whispering gallery mode resonator.